Apparatus and process for recovering scraps of thermoplastic material, even of heterogeneous shapes, by gradual melting and compression through one or more orifices

Abstract

Device for recovering thermoplastic materials comprising a hopper and downstream of the latter a chamber of decreasing cross-section, means for feeding to said chamber the material from the hopper, means for supplying heat to the material for gradually melting the material being fed in the chamber, one or more orifices being provided downstream of the chamber for the outlet or discharge of the material.

What I claim is: 
     
       1. An apparatus for recovering homogeneous or heterogeneous thermoplastic materials, comprising a hopper into which the material is introduced, a chamber downstream of said hopper, the chamber being of decreasing cross-section, means for feeding the material along said chamber from said hopper, and means for supplying heat to the material, so that the latter gradually melts in its forward movement in the chamber, the material on forward moving being compressed to the most restricted zone and being then forced to the outside through one or more orifices. 
     
     
       2. An apparatus according to claim 1, wherein said chamber comprises the space between the outer surface of a rotary cylinder or drum and the inner surface of a cylindrical casing accomodating said rotary cylinder or drum and which is eccentrical relative to the latter, means being provided for rotating said cylinder at an adjustable speed, means for heating at an adjustable temperature said rotary cylinder or drum, and means for heating still at predetermined temperatures said cylindrical casing, so that the apparatus can gradually and continuously melt any thermoplastic material, compressing the latter by viscoelastic draw between said heated rotary cylinder or drum and said eccentrical as well heated casing. 
     
     
       3. An apparatus according to claim 1, comprising downstream of said decreasing cross-section chamber a die, so that the apparatus enables to provide one or more continuous cylindrical or polygonal webs from thermoplastic materials of heterogeneous shapes by a single operation through said die. 
     
     
       4. An apparatus according to claim 1, for continuously feeding an extruder located downstream of the apparatus for the production of plastic manufactured articles from thermoplastic materials of heterogeneous shape. 
     
     
       5. A process for recovering homogeneous or heterogeneous thermoplastic materials, wherein the material is introduced into a hopper and then the material is passed through a chamber of decreasing cross-section, while the material is heated to gradually melt as it moves forward in said chamber, on forward moving said material being compressed to the most restricted zone and being then forced to the outside through one or more orifices. 
     
     
       6. An apparatus according to claim 2, comprising downstream of said decreasing cross-section chamber a die, so that the apparatus enables to provide one or more continuous cylindrical or polygonal webs from thermoplastic materials of heterogeneous shapes by a single operation through said die. 
     
     
       7. An apparatus according to claim 2, for continuously feeding an extruder located downstream of the apparatus for the production of plastic manufactured articles from thermoplastic materials of heterogeneous shape.